My wife has a 2002 9-3 SE has no crayon smell, but she used to have a 1999 Viggen with the crayon smell.
I love it.
My girl's Viggen was the lightning blue coupe. She sold it when she got into grad school. We often talk about getting another...
Anyhow, back to the topic, I tend to agree with one of the commenters on the Dell forums. This doesn't sound like glue, or preservative, or actual cat piss. This sounds like a defect in the plastics manufacturing process, perhaps a bad batch of some component chemical. Not sure if these laptops came from China but tainted or counterfeit industrial products are common there. It's possible that a sub-contractor or sub-sub-contractor manufactured these plastic pieces and they slipped by QC. I can't imagine a laptop manufacturer even doing "smell testing" on their products and it's easy to see how this might have escaped notice by the assembly line workers, especially if they're working in a factory town with awful air pollution.